Australian news, and some related international items

Busting the pro thorium nuclear spin

Should Australia consider thorium nuclear power? The Conversation Nigel Marks, Associate Professor of Physics, Curtin University March 2, 2015 “…….. a growing community of devotees has sprung up around an alternative nuclear fuel: thorium. But is it right for Australia?

……Today, advocates of thorium typically point to a variety of advantages over uranium. These include fail-safe reactor operation, because most thorium reactor designs are incapable of an explosion or meltdown, as was seen at Chernobyl or Fukushima. Another is resistance to weapons proliferation, because thorium reactors create byproducts that make the fuel unsuitable for use in nuclear weapons.Other advantages include greater abundance of natural reserves of thorium, less radioactive waste and higher utilisation of fuel in thorium reactors. Thorium is often cast as “good nuclear”, while uranium gets to carry the can as “bad nuclear”.

Not so different

While compelling at first glance, the details reveal a somewhat more murky picture. The molten salt architecture which gives certain thorium reactors high intrinsic safety equally applies to proposed fourth-generation designs using uranium. It is also true that nuclear physics technicalities make thorium much less attractive for weapons production, but it is by no means impossible; the USA and USSR each tested a thorium-based atomic bomb in 1955.

Other perceived advantages similarly diminish under scrutiny. There is plenty of uranium ore in the world and hence the fourfold abundance advantage of thorium is a moot point. Producing less long-lived radioactive waste is certainly beneficial, but the vexed question remains of how to deal with it.

Stating that thorium is more efficiently consumed is the most mischievous of the claimed benefits. Fast-breeder uranium reactors have much the same fuel efficiency as thorium reactors. However, they weren’t economic as the price of uranium turned out to rather low.